Need help about SPAM

Clarifications

The blacklisting in RBL is a separate issue, which may have been caused by some other company using your ISP - unless you know that only your particular domain is blacklisted, not a block of IP addresses.

Have you had any tests done to see if your mail server is an open relay?

If you have a spare PC, you could install one of the Linux distributions which usually comes with a mail server like Sendmail, Spamassassin and an anti-virus application like Clam. TR has some resources regarding Spamassassin, including a suggested project planning kit.

Because these products can be downloaded free of charge, some of the user interfaces are sometimes not that easy to use. However, Open Source applications like Webmin should allow you to do the systems administration without too many problems. The key thing is to get the skills by doing and learning, or to get a specialist to do the installation and configuration first. Please note that the server can be administered remotely, if required.

Ditch the windows-based software, it's not up to the job. I could recommend many packages that are - but they all require some experience to configure, and so this learning process is your first job. Maybe find yourself and old PC - install linux, sendmail, procmail, and qpopper (or any equivalents) and get playing. Someone else has already suggested Webmin - very good idea if you need pictures.

This is going to take some learning as these packages are big, powerful, and rambling.

Engage a consultant or specialist and it'll be sorted pretty quickly. Don't go and buy MS exchange, or whatever it is these days, server - it's pants.

RBL don't blacklist domains - they only hold records of IP addresses. Don't mess about trying to get unlisted, switch ISP NOW! your current ISP is either unaware one of their addresses is listed - so they don't care about this, or they know and they don't care. You should move quickly to a clean ISP - maybe one that can get you started with your own local MX.